Relationships of ABO and Rhesus blood groups with type 2 diabetes mellitus: a systematic review and meta-analysis

OBJECTIVES: The susceptibility to type 2 diabetes mellitus (T2DM) has been linked to blood type. We aimed to characterize the relationships of the ABO and Rhesus blood groups with T2DM. METHODS: Literature searches were performed using the Medline, PubMed, Scopus, Cochrane, EMBASE, and Google Scholar databases to identify studies published up to 31 March 2022. The PRISMA guidelines were used for reporting. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were obtained using fixed-effects models. RESULTS: Twenty-six studies of 6870 patients with T2DM and 11,879 controls were identified. Compared with the other ABO groups, people with blood type B were at higher risk of T2DM (OR: 1.30, 95% CI: 1.20–1.41), while group O was associated with a lower risk (OR: 0.92, 95% CI: 0.86–0.98). There were no significant associations of T2DM with blood types A or AB, or Rh factor. CONCLUSION: Individuals with blood type B are at higher risk of developing T2DM. Therefore, they should be screened for T2DM on a frequent basis and be made aware of the importance of maintaining a balanced diet and regular exercise for the prevention of obesity and T2DM. PROSPERO REGISTRATION NUMBER: CRD42022353945.